Porting potential of GT40 Vs early 351W heads

I've got a set of early 351W heads that look to be in good shape that I was planning on porting and having them rebuilt. I think I found a complete 96 Explorer 5.0L that's in great shape, so I was wondering about how the GT40s compare to the 351W heads as far as performance after they've been ported? I was under the impression that all iron SBF heads came out about the same when ported?
Thanks
--Kyle

The GT 40's will make more power. How much depends on your build but typiacally it's around 20-30 more HP.
It's not hard to improve upon the stock sb stuff...

Originally Posted by ou812

The GT 40's will make more power. How much depends on your build but typiacally it's around 20-30 more HP.
It's not hard to improve upon the stock sb stuff...

Are you talking stock form? I would be surprised there would be much of a difference between the two after porting. I believe the GT-40s referred to here are the GT-40Ps and the 351w heads are either '69 or '70 C90E or D00E heads.

I correct myself, I just read the Ps didn't come along until 1997 and your heads are coming out of a 96 Explorer.

Found an article that has some comparison data for stock GT-40 and GT-40Ps here under "Articles"

StangPro.com

Here is a site that has comparison data for ported GT-40s and '70 351w heads (DOOE)

Cast Iron Heads